Brushes



E. TROTIN BRUSHES Oct. 27, 1964 Filed Aug. 30, 1962 ORNEYS United States Patent 3,153,860 BRUSHES Etienne Trotin, Paris, France, assignor to Scciete Rhediaceta, aris, France, a corporation of France Filed Aug. 30, 1962, Ser. No. 220,546 Claims priori application France Sept. 6, 1961 4 Claims. (-Cl. 15-159) This invention relates to new types of brushes.

Since the appearance on the market of course synthetic monofilaments, and especially those based on polyamides, numerous suggestions have been made for using them because of their mechanical resistance qualities, to replace or partly to replace animal bristles in the manufacture of brushes. The coarse synthetic monofilaments are manufactured in the continuous form and are then cut to the length suitable for the proposed use.

With the object of producing coarse tapered monofilaments, special extrusion means has been devised for extruding such coarse monofilaments, having a section which increases and decreases periodically. After cutting at the level of the thicker and/ or thinner portions, tapered bristles are obtained, which are used more particularly for the manufacture of paint brushes and the like.

It has been difiicult to obtain a suficiently Wide range of hardness values in the bristles for all types of brushes Without affecting other characteristics, such as pliability, resistance to flattening, etc.

The new brushes of the present invention are formed at least in part of synthetic bristles having a diameter which varies along the length of the bristle and the said bristles are so arranged in any one tuft that the parts of larger diameter are offset from one another along the length of the tuft.

The expression parts of larger diameter are oli'set from one another along the length of the tuft implies in any cross-section of the tuft perpendicular to its len th, relatively thick parts of some bristles will occur and relatively thin parts of others.

This ofisetting of the parts of greater diarneter may be distributed regularly or at random.

The bristles used may in addition show differences in length, which again may or may not be at random.

The new type of brush may be made by assembling together a number of monofilaments sufficient to form a tuft, at least a part of which consists of synthetic monofilaments composed of a series of tapered zones, the assembling being carried out so that the parts of said monofilaments of larger diameter are offset from one another along the length of the assembly, cutting the assembly into sections of the required length to form tufts and forming a brush from one such tuft (a simple brush) or from a number of tufts (a compound brush).

The invention is illustrated by the accompanying drawing in which FIGURE 1 is a side elevation of a brush according to the invention;

FlG. 2 is a transverse section taken on the line Z2 of FIG. 1; and

FIG. 3 is a transverse section taken on the line 33 of FIG. 1.

For the sake of clarity, the diameters of the filaments are considerably exaggerated.

From FIGS. 2 and 3, the random distribution of the varying diameters of the different filaments is at once apparent. Moreover, each filament is shown in the same relative position in these two figures.

While the invention may be applied to the production of brushes of all types, it is particularly applicable to paint brushes, soft brushes and hair brushes.

The invention has the advantage that it is possible for 3,1535% Patented Oct. 27, 1964 Ice the hardness and stiffness of the brushes obtained to be modified witn'n very Wide limits by choosing the extreme values of the diameters of the coarse monofilaments and the period of their variations, the latter, in conjunction with the cutting length, providing various ranges in diameter of the diiferent bristles. For example, for hair brushes, it is advantageous to use diameters varying from 0.15 to 0.23 mm.

Further, the brushes obtained have an appearance which is surprisingly similar to that of brushes made from animal bristles, more especially when the bristles have been dyed beforehand (see more particularly Example 1 as given below).

The bristles used are preferably based on polycondensation products, such as polyamides or polyesters, but may alternatively be based on other synthetic polymers for example polyurethanes, polyolefines or polyvinyl derivatives. The section of the bristles may for example be circular or triiobal or cruciform.

Mixtures of bristles may be used with diameters having extreme values difiering from one bristle to the other. Generally the bristles of varying diameter used in the present invention may be associated in the tufts of the brushes, in intimate mixture or not, with bristles of animal origin such as pig bristles and/or with synthetic ristles of which the section may be substantially constant and may be circular or non-circular, e.g. trilobal or cruciform, and/ or with synthetic bristles of a different nature, the diameter of which also varies along the bristle length.

Before or after being mounted, the bristles may be subjected to a tapering and/ or a lla ng, accor ing to known processes, for example by means of a device comprising a blade rotating at high velocity and with the aid of needles, which may or may not be sharp, which are adapted to strike the ends of the bristles.

The bristles used may further be corrugated beforehand by processes known per se, for example, in the case of making paint brushes, to improve their retentive power for the paint.

The invention is illustrated by the following examples in which the percentages are by weight.

Example I For the manufacture of a hair brush, an assembly is formed of monofilamerits with a length of about 1 metre and based on polyhexamethylene sebacamide, this mixture being formed, in proportions of 50/50 by weight, by:

Monofilarnents of which the diameter varies from 0.15 to 0.23 with a period of and dyed yellow,

Monofilarnents of which the diameter varies from 0.20 to 0.30 mm., also with a period of 140 mm, 60% of which are of natural colour and 40% are dyed grey, the position of th sections of larger diameter being offset at random from one mon-oiilament to the other in the mixture.

The assembly is cut into sections having a length of 60 min, which are used for the manufacture of the tufts of the brush.

The brush whi h is obtained has a very striking resemblance to a pig bristle brush and has in addition much better qualities as regards resistance to wear.

Example 11 For the purpose of obtaining a brush having a better degree of hardness, the mixture of monofilanients according to Example I is again used together with 20% of cylindrical monofilaments with a diameter of 0.50 mm. and based on polyhexamethylene adipamide.

Example 111 A hair brush is manufactured, using the mixture of monofilaments indicated in Example I, to which 15% of pig bristles are added.

Example IV length, having a cruciform section, and this mixture is p I used for the manufacture of the brush.

Example V A brush, which can for example be used in the textile industry for removing the waste from the combs, is manufactured from polypropylene monofilaments, the diameter of which varies from 0.15 to 0.23 mm. with a peroid of 120 mm., cut into sections with a length of 40 mm., in the manner indicated in the previous examples. The

bristles are used dyed in the mass, 50% being dyed grey I v and 50% beige.

I claim:

1. A brush selected from the group which consists of paint brushes, soft brushes and hair brushes, the bristles of which brush are at least in part synthetic monofilaments composed of a series of tapered zones such that the diameters of the monofilaments vary continuously along the lengths thereof, the said monofilaments being so arranged in any one tuft that the parts of maximum diameter in adjacent monofilaments are ofiset axially from one another along the length of the tuft.

2. A brush selected from the group which consists of paint brushes, soft brushes and hair brushes, the bristles of which brush are at least in part synthetic monofilaments composed of a series of tapered Zones such that the diameters of the monofilaments vary continuously along the lengths thereof and that in each of the said monofilaments the diameter reaches its maximum value once only in the length of the monofilament, the said monofilaments being so arranged in any one tuft that the parts of maximum diameter in adjacent monofilaments are offset axially from one another along the length of the tuft.

3. A hair brush, the bristles of which are at least in part synthetic monofilaments composed of a series of tapered zones such that the diameters of the monofilaments vary continuously within the range from 0.15 to 0.23 mm. along the lengths or" the said monofilaments, the said monofilaments being so arranged in any one tuft that the parts of maximum diameter in adjacent monofilaments are offset axially from one another along the length of the tuft.

4. A hair brush, the bristles of which are in part synthetic monofilaments composed of a series of tapered Zones such that the diameters of the monofilaments vary continuously within the range from 0.15 to 0.23 mm. along the lengths of the said monofilaments and that in each of the said monofilaments the diameter reaches its maximum value once only in the length of the monofilament, the said monofilaments being so arranged in any one tuft that the parts of maximum diameter in adjacent monofilaments are offset axially from one another along the length of the tuft.

References Cited in the file of this patent UNITED STATES PATENTS 2,423,182 Fields July 1, 1947 2,433,325 Slaughter Dec. 23, 1947 2,443,055 Reis June 8, 1943 2,455,759 Gregory Dec. 7, 1948 2,508,799 Reis May 23, 1950 2,580,378 Peterson et a1 Dec. 25, 195.1 2,666,976 Olmer et a1 Jan. 26, 1954 2,320,986 Seny Jan. 28, 1958 2,866,256 Matlin Dec. 30, 1958 2,917,779 Kur zke et a1 Dec. 22, 1959 2,947,598 Maragliano et al. Aug. 2, 1960 3,090,061 Charvat May 21, 1963 FOREIGN PATENTS 598,821 Great Britain Feb. 26, 1948 603,173 Great Britain June 10, 1948 at least I 

1. A BRUSH SELECTED FROM THE GROUP WHICH CONSISTS OF PAINT BRUSHES, SOFT BRUSHES AND HAIR BRUSHES, THE BRISTLES OF WHICH BRUSH ARE AT LEAST IN PART SYNTHETIC MONOFILAMENTS COMPOSED OF A SERIES OF TAPERED ZONES SUCH THAT THE DIAMETERS OF THE MONOFILAMENTS VARY CONTINUOUSLY ALONG THE LENGTHS THEREOF, THE SAID MONOFILAMENTS BEING 